Crenolanib for treating FLT3 mutated proliferative disorders

ABSTRACT

The present invention relates to the use of crenolanib, in a pharmaceutically acceptable salt form for the treatment of FLT3 mutated proliferative disorders driven by constitutively activated mutant FLT3, and to a method of treatment of warm-blooded animals, preferably humans, in which a therapeutically effective dose of crenolanib is administered to an animal suffering from said disease or condition:

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application Ser.No. 61/749,695, filed Jan. 7, 2013, the entire content of which isincorporated herein by reference.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to the use of crenolanib, in apharmaceutically acceptable salt form for the treatment of FLT3 mutatedproliferative disorder(s) driven by constitutively activated mutantFLT3, and to a method of treatment of warm-blooded animals, preferablyhumans, in which a therapeutically effective dose of crenolanib isadministered to a subject suffering from said disease or condition.

STATEMENT OF FEDERALLY FUNDED RESEARCH

None.

INCORPORATION-BY-REFERENCE OF MATERIALS FILED ON COMPACT DISC

None.

BACKGROUND OF THE INVENTION

Without limiting the scope of the invention, its background is describedin connection with FLT3 tyrosine kinase.

The FMS-like tyrosine kinase 3 (FLT3) gene encodes a membrane boundreceptor tyrosine kinase that affects hematopoiesis leading tohematological disorders and malignancies. See Drexler, H G et al.Expression of FLT3 receptor and response to FLT3 ligand by leukemiccells. Leukemia. 1996; 10:588-599; Gilliland, D G and J D Griffin. Theroles of FLT3 in hematopoiesis and leukemia. Blood. 2002; 100:1532-1542;Stirewalt, D L and J P Radich. The role of FLT3 in hematopoieticmalignancies. Nat Rev Cancer. 2003; 3:650-665. Activation of FLT3receptor tyrosine kinases is initiated through the binding of the FLT3ligand (FLT3-L) to the FLT3 receptor, also known as Stem cell tyrosinekinase-1 (STK-1) and fetal liver kinase-2 (flk-2), which is expressed onhematopoietic progenitor and stem cells.

FLT3 is one of the most frequently mutated genes in hematologicalmalignancies, present in approximately 30% of adult acute myeloidleukemias (AML). See Nakao M, S Yokota and T Iwai. Internal tandemduplication of the FLT3 gene found in acute myeloid leukemia. Leukemia.1996; 10:1911-1918; H Kiyoi, M Towatari and S Yokota. Internal Tandemduplication of the FLT3 gene is a novel modality of elongation mutation,which causes constitutive activation of the product. Leukemia. 1998;12:1333-1337; P D Kottaridis, R E Gale, et al. The presence of a FLT3internal tandem duplication in patients with acute myeloid leukemia(AML) adds important prognostic information to cytogenetic risk groupand response to the first cycle of chemotherapy: analysis of 854patients from the United Kingdom Medical Research Council AML 10 and 12trials. Blood. 2001; 98:1742-1759; Yamamoto Y, Kiyoi H, Nakano Y.Activating mutation of D835 within the activation loop of FLT3 in humanhematologic malignancies. Blood. 2001; 97:2434-2439; Thiede C, CSteudel, Mohr B. Analysis of FLT3-activating mutations in 979 patientswith acute myelogenous leukemia: association with FAB subtypes andidentification of subgroups with poor prognosis. Blood. 2002;99:4326-4335.

The most common FLT3 mutations are internal tandem duplications (ITDs)that lead to in-frame insertions within the juxtamembrane domain of theFLT3 receptor. FLT3-ITD mutations have been reported in 15-35% of adultAML patients. See Nakao M, S Yokota and T Iwai. Internal tandemduplication of the FLT3 gene found in acute myeloid leukemia. Leukemia.1996; 10:1911-1918; H Kiyoi, M Towatari and S Yokota. Internal Tandemduplication of the FLT3 gene is a novel modality of elongation mutation,which causes constitutive activation of the product. Leukemia. 1998;12:1333-1337; H Kiyoi, T Naoe and S Yokota. Internal tandem duplicationof FLT3 associated with leukocytosis in acute promyelocytic leukemia.Leukemia Study Group of the Ministry of Health and Welfare (Kohseisho).Leukemia. 1997; 11:1447-1452; S Schnittger, C Schoch and M Duga.Analysis of FLT3 length mutations in 1003 patients with acute myeloidleukemia: correlation to cytogenetics, FAB subtype, and prognosis in theAMLCG study and usefulness as a marker for the detection of minimalresidual disease. Blood. 2002; 100:59-66. A FLT3-ITD mutation is anindependent predictor of poor patient prognosis and is associated withincreased relapse risk after standard chemotherapy, and decreaseddisease free and overall survival. See F M Abu-Duhier, Goodeve A C,Wilson G A, et al. FLT3 internal tandem duplication mutations in adultacute myeloid leukemia define a high risk group. British Journal ofHaematology. 2000; 111:190-195; H Kiyoi, T Naoe, Y Nakano, et al.Prognostic implication of FLT3 and N-RAS gene mutations in acute myeloidleukemia. Blood. 1999; 93:3074-3080.

Less frequent are FLT3 point mutations that arise in the activation loopof the FLT3 receptor. The most commonly affected codon is aspartate 835(D835). Nucleotide substitutions of the D835 residue occur inapproximately 5-10% of adult AML patients. See D L Stirewalt and J PRadich. The role of FLT3 in haematopoietic malignancies. Nature ReviewsCancer. 2003; 3:650-665; Y Yamamoto, H Kiyoi and Y Nakano, et al.Activating mutation of D835 within the activation loop of FLT3 in humanhematologic malignancies. Blood. 2001; 97:2434-2439; C Thiede, SteudalC, Mohr B, et al. Analysis of FLT3-activating mutations in 979 patientswith acute myelogenous leukemia: association with FAB subtypes andidentification of subgroups with poor prognosis. Blood. 2002;99:4326-4335; U Bacher, Haferlach C, W Kern, et al. Prognostic relevanceof FLT3-TKD mutations in AML: the combination matters-an analysis of3082 patients. Blood. 2008; 111:2527-2537.

The heightened frequency of constitutively activated mutant FLT3 inadult AML has made the FLT3 gene a highly attractive drug target in thistumor type. Several FLT3 inhibitors with varying degrees of potency andselectivity for the target have been or are currently being investigatedand examined in AML patients. See T Kindler, Lipka D B, and Fischer T.FLT3 as a therapeutic target in AML: still challenging after all theseyears. Blood. 2010; 116:5089-102.

FLT3 inhibitors known in the art include Lestaurtinib (also known as CEP701, formerly KT-555, Kyowa Hakko, licensed to Cephalon); CHIR-258(Chiron Corp.); EB10 and IMC-EB10 (ImClone Systems Inc.); Midostaurin(also known as PKC412, Novartis AG); Tandutinib (also known as MLN-518,formerly CT53518, COR Therapeutics Inc., licensed to MillenniumPharmaceuticals Inc.); Sunitinib (also known as SU11248, Pfizer USA);Quizartinib (also known as AC220, Ambit Biosciences); XL 999 (ExelixisUSA, licensed to Symphony Evolution, Inc.); GTP 14564 (Merck BiosciencesUK); AG1295 and AG1296; CEP-5214 and CEP-7055 (Cephalon). The followingPCT International Applications and U.S. patent applications discloseadditional kinase modulators, including modulators of FLT3: WO2002032861, WO 2002092599, WO 2003035009, WO 2003024931, WO 2003037347,WO 2003057690, WO 2003099771, WO 2004005281, WO 2004016597, WO2004018419, WO 2004039782, WO 2004043389, WO 2004046120, WO 2004058749,WO 2004058749, WO 2003024969 and U.S Patent Application No, 20040049032.See also Levis M, KF Tse, et al. 2001 “A FLT3 tyrosine kinase inhibitoris selectively cytotoxic to acute myeloid leukemia blasts harboring FLT3internal tandem duplication mutations.” Blood 98(3): 885-887; Tse K F,et al., Inhibition of FLT3-mediated transformation by use of a tyrosinekinase inhibitor. Leukemia. July 2001; 15 (7): 1001-1010; Smith, B.Douglas et al., Single agent CEP-701, a novel FLT3 inhibitor, showsbiologic and clinical activity in patients with relapsed or refractoryacute myeloid leukemia Blood, May 2004; 103: 3669-3676; Griswold, Ian J.et al., Effects of MLN518, A Dual FLT3 and KIT Inhibitor, on Normal andMalignant Hematopoiesis. Blood, November 2004; 104 (9): 2912-2918 [Epubahead of print July 8]; Yee, Kevin W. H. et al., SU5416 and SU5614inhibit kinase activity of wild-type and mutant FLT3 receptor tyrosinekinase. Blood, October 2002; 100(8): 2941-2949. O'Farrell, Anne-Marie etal., SU11248 is a novel FLT3 tyrosine kinase inhibitor with potentactivity in vitro and in vivo. Blood, May 2003; 101(9): 3597-3605;Stone, R. M et al., PKC-412 FLT3 inhibitor therapy in AML: results of aphase II trials. Ann. Hematol. 2004; 83 Suppl 1:589-90; and Murata, K.et al., Selective cytotoxic mechanism of GTP-14564, a novel tyrosinekinase inhibitor in leukemia cells expressing a constitutively activeFms-like tyrosine kinase 3 (FLT3). J Biol. Chem. Aug. 29, 2003; 278(35): 32892-32898 [Epub 2003 Jun. 18]; Levis, Mark et al., SmallMolecule FLT3 Tyrosine Kinase Inhibitors. Current Pharmaceutical Design,2004, 10, 1183-1193.

The aforementioned inhibitors have either been or are currently beinginvestigated in the preclinical setting, or phase I and II trials asmonotherapy in relapsed AML, or in phase III combination studies inrelapsed AML. Despite reports of successful inhibition of FLT3 withthese compounds in preclinical studies, complete remissions have rarelybeen achieved in FLT3 mutant AML patients in the clinical setting. Inthe majority of patients, the clinical response is short-lived. Responsecriteria for AML clinical trials are adapted from the InternationalWorking Group for AML. See Cheson et al. Revised Recommendations of theInternational Working Group for Diagnosis, Standardization of ResponseCriteria, Treatment Outcomes, and Reporting Standards for TherapeuticTrials in Acute Myeloid Leukemia. J Clin Oncol. 2003; 21: 4642-4649.Responders are patients who obtain a Complete Response (CR), CompleteResponse with incomplete blood count recovery (CRi), or PartialRemission (PR). Briefly, criteria are as follows:

1. Complete Remission (CR):

-   -   a. Peripheral blood counts:        -   i. No circulating blasts        -   ii. Neutrophil count ≧1.0×10⁹/L        -   iii. Platelet count ≧100×10⁹/L    -   b. Bone marrow aspirate and biopsy:        -   i. ≦5% blasts        -   ii. No Auer Rods        -   iii. No extramedullary leukemia

2. Complete remission with incomplete blood count recovery (CRi):

-   -   a. Peripheral blood counts:        -   i. No circulating blasts        -   ii. Neutrophil count <1.0×10⁹/L, or        -   iii. Platelet count <100×10⁹/L    -   b. Bone marrow aspirate and biopsy        -   i. ≦5% blasts        -   ii. No Auer Rods        -   iii. No extramedullary leukemia

3. Partial remission:

-   -   a. All CR criteria if abnormal before treatment except:    -   b. ≧50% reduction in bone marrow blast but still >5%

To date, clinical responses to FLT3 inhibitors have been primarilylimited to clearance of peripheral blood (PB) blasts, which frequentlyreturn within a matter of weeks, while bone marrow (BM) blasts remainlargely unaffected. For example, treatment with sorafenib, the priormentioned multi-kinase inhibitor with activity against mutant FLT3,while effective in clearing PB blasts, has resulted in only modest BMblast reductions. See G Borthakur et al. Phase I study of sorafenib inpatients with refractory or relapsed acute leukemias. Haematologica.January 2011; 96: 62-8. BM blast percentage plays a central role in thediagnosis and classification of AML. The presence of a heightenedpercentage of blasts in BM is associated with significantly shorteroverall survival. See Small D. FLT3 mutations: biology and treatment.Hematology Am Soc Hematol Educ Program. 2006: 178-84; HM Amin et al.Having a higher blast percentage in circulation than bone marrow:clinical implications in myelodysplastic syndrome and acute lymphoid andmyeloid leukemias. Leukemia. 2005; 19: 1567-72. To effectively treatFLT3 mutated AML patients and overcome the significant unmet need inthis patient population, an inhibitor that significantly depletes bothPB and BM blasts, bridge high risk and heavily pretreated patients tostem cell transplant, and can help to decrease relapse rates andincrease overall survival in early stage disease patients. The currentinvention seeks to overcome disadvantages of the prior art.

SUMMARY OF THE INVENTION

In one embodiment, the present invention includes a method for treatinga FLT3 mutated proliferative disorder in a patient which comprisesadministering to the patient a therapeutically effective amount ofcrenolanib or a pharmaceutically acceptable salt thereof. In one aspect,the method may also include identifying a patient with a proliferativedisorder selected from at least one of a leukemia, myeloma,myeloproliferative disease, myelodysplastic syndrome, idiopathichypereosinophilic syndrome (HES), bladder cancer, breast cancer,cervical cancer, CNS cancer, colon cancer, esophageal cancer, head andneck cancer, liver cancer, lung cancer, nasopharyngeal cancer,neuroendocrine cancer, ovarian cancer, pancreatic cancer, prostatecancer, renal cancer, salivary gland cancer, small cell lung cancer,skin cancer, stomach cancer, testicular cancer, thyroid cancer, uterinecancer, and hematologic malignancy. In another aspect, thetherapeutically effective amounts of crenolanib or a pharmaceuticallyacceptable salt thereof are from about 50 to 500 mg per day, 100 to 450mg per day, 200 to 400 mg per day, 300 to 500 mg per day, 350 to 500 mgper day, or 400 to 500 mg per day. In another aspect, the crenolanib ora pharmaceutically acceptable salt thereof is administered at least oneof continuously, intermittently, systemically, or locally. In anotheraspect, the mutated FLT3 is defined further as a constitutively activeFLT3 mutant. In another aspect, the crenolanib or a pharmaceuticallyacceptable salt thereof is administered orally, intravenously, orintraperitoneally. In another aspect, the crenolanib or apharmaceutically acceptable salt thereof is crenolanib besylate,crenolanib phosphate, crenolanib lactate, crenolanib hydrochloride,crenolanib citrate, crenolanib acetate, crenolanib toluenesulphonate andcrenolanib succinate. In another aspect, the FLT3 is at least one ofFLT3-ITD or FLT3-TKD. In another aspect, the therapeutically effectiveamount of crenolanib or a pharmaceutically acceptable salt thereof isadministered up to three times or more a day for as long as the subjectis in need of treatment for the proliferative disorder. In anotheraspect, the crenolanib or a pharmaceutically acceptable salt thereof isprovided at least one of sequentially or concomitantly, with anotherpharmaceutical agent in a newly diagnosed proliferative disorderpatient, to maintain remission of an existing patient, or arelapsed/refractory proliferative disease patient. In another aspect,the crenolanib or a pharmaceutically acceptable salt thereof is providedas a single agent or in combination with another pharmaceutical agent ina patient with a newly diagnosed proliferative disorder, to maintainremission, or a relapsed/refractory proliferative disease patient. Inanother aspect, the crenolanib or a pharmaceutically acceptable saltthereof is provided as a single agent or in combination with anotherpharmaceutical agent in a newly diagnosed proliferative disorderpediatric patient, to maintain remission, or a relapsed/refractoryproliferative disorder pediatric patient. In another aspect, the patientis relapsed/refractory to other FLT3 tyrosine kinase inhibitors.

Another embodiment of the present invention includes a method fortreating a patient suffering from a proliferative disease comprising:identifying the patient in need of therapy for the proliferativedisease; and administering to the patient in need of such treatment atherapeutically effective amount of Crenolanib or a salt thereof,wherein the cell proliferative disorder is characterized by deregulatedFLT3 receptor tyrosine kinase activity, wherein the proliferativedisease is selected from at least one of a leukemia, myeloma,myeloproliferative disease, myelodysplastic syndrome, idiopathichypereosinophilic syndrome (HES), bladder cancer, breast cancer,cervical cancer, CNS cancer, colon cancer, esophageal cancer, head andneck cancer, liver cancer, lung cancer, nasopharyngeal cancer,neuroendocrine cancer, ovarian cancer, pancreatic cancer, prostatecancer, renal cancer, salivary gland cancer, small cell lung cancer,skin cancer, stomach cancer, testicular cancer, thyroid cancer, uterinecancer, and hematologic malignancy. In one aspect, the crenolanib or apharmaceutically acceptable salt thereof is administered orally,intravenously, or intraperitoneally. In another aspect, the crenolanibor a pharmaceutically acceptable salt thereof is at least one ofCrenolanib Besylate, Crenolanib Phosphate, Crenolanib Lactate,Crenolanib Hydrochloride, Crenolanib Citrate, Crenolanib Acetate,Crenolanib Touluenesulphonate and Crenolanib Succinate CrenolanibBesylate. In another aspect, the FLT3 is at least one of FLT3-ITD orFLT3-TKD. In another aspect, the crenolanib or a pharmaceuticallyacceptable salt thereof is provided at least one of sequentially orconcomitantly, with another chemotherapeutic agent in a newly diagnosedproliferative disease, to maintain remission, or a relapsed/refractoryproliferative disease. In another aspect, the crenolanib or apharmaceutically acceptable salt thereof is provided as a single agentor in combination with another chemotherapeutic agent for treatment ofpediatric patient with the proliferative disease. In another aspect, thecrenolanib or a pharmaceutically acceptable salt thereof is provided asa single agent to at least one of post standard induction therapy, orhigh dose induction therapy, in newly diagnosed proliferative disease.In another aspect, the crenolanib or a pharmaceutically acceptable saltthereof is provided as a single agent in treatment of patients with theproliferative disease that is either refractory to, or has relapsedafter prior treatment with a chemotherapeutic agent. In another aspect,the patient is refractory to at least one other tyrosine kinaseinhibitor.

Yet another embodiment of the present invention includes a method fortreating a patient suffering from leukemia comprising: obtaining asample from the patient suspected of having a leukemia; determining fromthe patient sample that the patient has a deregulated FLT3 receptortyrosine kinase; and administering to the patient in need of suchtreatment a therapeutically effective amount of Crenolanib or a saltthereof, wherein the leukemia is characterized by deregulated FLT3receptor tyrosine kinase activity. In one aspect, the leukemia isselected from Hodgkin's disease, and myeloma, acute lymphocytic leukemia(ALL), acute myeloid leukemia (AML), acute promyelocytic leukemia (APL),chronic lymphocytic leukemia (CLL), chronic myeloid leukemia (CML),chronic neutrophilic leukemia (CNL), acute undifferentiated leukemia(AUL), anaplastic large-cell lymphoma (ALCL), prolymphocytic leukemia(PML), juvenile myelomonocytic leukemia (JMML), adult T-cell ALL, AML,with trilineage myelodysplasia (AMLITMDS), mixed lineage leukemia (MLL),myelodysplastic syndromes (MDSs), myeloproliferative disorders (MPD),and multiple myeloma (MM).

Yet another embodiment of the present invention includes a method forspecifically inhibiting a deregulated receptor tyrosine kinasecomprising: obtaining a patient sample and determining which receptortyrosine kinases are deregulated; and administering to a mammal in needof such treatment a therapeutically effective amount of crenolanib or asalt thereof, wherein the deregulated receptor tyrosine kinase is a FLT3receptor tyrosine kinase. In one aspect, the therapeutically effectiveamount of crenolanib or a salt thereof is provided in an amount thatdecreases patient circulating peripheral blood blast count. In anotheraspect, the therapeutically effective amount of crenolanib or a saltthereof is provided in an amount that decreases a patient bone marrowblast count. In another aspect, the proliferative disease is selectedfrom at least one of a leukemia, myeloma, myeloproliferative disease,myelodysplastic syndrome, idiopathic hypereosinophilic syndrome (HES),bladder cancer, breast cancer, cervical cancer, CNS cancer, coloncancer, esophageal cancer, head and neck cancer, liver cancer, lungcancer, nasopharyngeal cancer, neuroendocrine cancer, ovarian cancer,pancreatic cancer, prostate cancer, renal cancer, salivary gland cancer,small cell lung cancer, skin cancer, stomach cancer, testicular cancer,thyroid cancer, uterine cancer, and hematologic malignancy. In anotheraspect, the therapeutically effective amount can also be aprophylactically effective amount of crenolanib or a salt thereof andare from about 50 to 500 mg per day, 100 to 450 mg per day, 200 to 400mg per day, 300 to 500 mg per day, 350 to 500 mg per day, or 400 to 500mg per day. In another aspect, the crenolanib or a salt thereof isadministered at least one of continuously, intermittently, systemically,or locally. In another aspect, the deregulated FLT3 is defined furtheras a mutated FLT3 is constitutively active. In another aspect, thecrenolanib or a salt thereof is administered orally, intravenously, orintraperitoneally. In another aspect, the crenolanib or a salt thereofis at least one of Crenolanib Besylate, Crenolanib Phosphate, CrenolanibLactate, Crenolanib Hydrochloride, Crenolanib Citrate, CrenolanibAcetate, Crenolanib Touluenesulphonate and Crenolanib SuccinateCrenolanib Besylate. In another aspect, the FLT3 is at least one ofFLT3-ITD or FLT3-TKD. In another aspect, the therapeutically effectiveamount of the crenolanib or a salt thereof is administered up to threetimes or more a day for as long as the subject is in need of treatmentfor the proliferative disease. In another aspect, the patient isprovided treatment, and the method further comprises the steps of:obtaining one or more patient samples to determine the effect of thetreatment, and continuing treatment until the proliferative disease isreduced or eliminated. In another aspect, the crenolanib or a saltthereof is provided at least one of sequentially or concomitantly, withanother pharmaceutical agent in a newly diagnosed proliferative diseasepatient, to maintain remission, or a relapsed/refractory proliferativedisease patient. In another aspect, the crenolanib or a salt thereof isprovided as a single agent or in combination with another pharmaceuticalagent in a newly diagnosed proliferative disease patient, to maintainremission, or a relapsed/refractory proliferative disease patient. Inanother aspect, the crenolanib or a salt thereof is provided as a singleagent or in combination with another pharmaceutical agent in a newlydiagnosed proliferative disease pediatric patient, to maintainremission, or a relapsed/refractory proliferative disease pediatricpatient. In another aspect, the patient is relapsed/refractory to aprior tyrosine kinase inhibitor. Non-limiting examples of other FLT3inhibitors to which the proliferative disease or disorder is resistantincludes, e.g., Lestaurtinib (also known as CEP 701, Cephalon); CHIR-258(Chiron Corp.); EB10 and IMC-EB10 (ImClone Systems Inc.); Midostaurin(also known as PKC412, Novartis AG); Tandutinib (also known as MLN-518,Millennium Pharmaceuticals Inc.); Sunitinib (also known as SU11248,Pfizer USA); Quizartinib (also known as AC220, Ambit Biosciences); XL999 (Symphony Evolution, Inc.); GTP 14564 (Merck Biosciences UK); AG1295and AG1296; and CEP-5214 and CEP-7055 (Cephalon).

Yet another embodiment of the present invention includes a method fortreating a patient with a proliferative disease comprising: obtaining asample from the patient; determining if the patient that has becomeresistant to prior tyrosine kinase inhibitors; and administering atherapeutically effective amount of Crenolanib or a salt thereof toovercome the resistance to the prior protein tyrosine kinase inhibitors.This summary of the invention does not necessarily describe allnecessary features of the invention.

DETAILED DESCRIPTION OF THE INVENTION

While the making and using of various embodiments of the presentinvention are discussed in detail below, it should be appreciated thatthe present invention provides many applicable inventive concepts thatcan be embodied in a wide variety of specific contexts. The specificembodiments discussed herein are merely illustrative of specific ways tomake and use the invention and do not delimit the scope of theinvention.

To facilitate the understanding of this invention, a number of terms aredefined below. Terms defined herein have meanings as commonly understoodby a person of ordinary skill in the areas relevant to the presentinvention. Terms such as “a”, “an” and “the” are not intended to referto only a singular entity, but include the general class of which aspecific example may be used for illustration. The terminology herein isused to describe specific embodiments of the invention, but their usagedoes not delimit the invention, except as outlined in the claims.

The present invention comprises the use of the compounds of the presentinvention to treat disorders related to FLT3 kinase activity orexpression in a subject, e.g., deregulated FLT3 tyrosine kinaseactivity.

The compound is Crenolanib (4-Piperidinamine,1-[2-[5-[(3-methyl-3-oxetanyl)methoxy]-1H-benzimidazol-1-yl]-8-quinolinyl]) and its pharmaceuticallyacceptable salts, which are protein tyrosine kinase inhibitors selectivefor constitutively active FLT3 mutations, including FLT3 ITD and FLT3TKD mutations. Unlike prior FLT3 inhibitors in the art, the besylatesalt form of crenolanib has shown to be remarkably effective indepleting absolute circulating peripheral blood blasts and bone marrowblast percentages in heavily pretreated FLT3 mutant AML patients.

In one embodiment to this aspect, the present invention provides amethod for reducing or inhibiting the kinase activity of FLT3 in asubject comprising the step of administering a compound of the presentinvention to the subject.

As used herein, the term “subject” refers to an animal, such as a mammalor a human, who has been the object of treatment, observation orexperiment.

In other embodiments, the present invention provides therapeutic methodsfor treating a subject with a cell proliferative disorder driven byaberrant kinase activity of mutant FLT3. In one example, the inventionprovides methods for treating a cell proliferative disorder related tomutant FLT3, comprising administration of a therapeutically effectiveamount of a pharmaceutical composition comprising a compound of thepresent invention in a subject. Administration of the therapeutic agentcan occur upon manifestation of symptoms characteristic of the FLT3driven cell proliferative disorder, such that a disease or disordertreated.

As used herein, the term “therapeutically effective amount”, refers toan amount of active compound or pharmaceutical salt that elicits thebiological or medicinal response in a subject that is being sought by aresearcher, veterinarian, medical doctor or other clinician, whichincludes alleviation of the symptoms of the disease or disorder beingtreated. Methods for determining therapeutically effective doses forpharmaceutical compositions comprising a compound of the presentinvention are known in the art. Techniques and compositions for makinguseful dosage forms using the present invention are described in one ormore of the following references: Anderson, Philip O.; Knoben, James E.;Troutman, William G, eds., Handbook of Clinical Drug Data, TenthEdition, McGraw-Hill, 2002; Pratt and Taylor, eds., Principles of DrugAction, Third Edition, Churchill Livingston, N.Y., 1990; Katzung, ed.,Basic and Clinical Pharmacology, Ninth Edition, McGraw Hill, 20037ybg;Goodman and Gilman, eds., The Pharmacological Basis of Therapeutics,Tenth Edition, McGraw Hill, 2001; Remington's Pharmaceutical Sciences,20th Ed., Lippincott Williams & Wilkins., 2000; Martindale, The ExtraPharmacopoeia, Thirty-Second Edition (The Pharmaceutical Press, London,1999); relevant portions incorporated herein by reference.

As used herein, the term “composition” refers to a product comprisingthe specified ingredients in the specified amounts, as well as anyproduct, which results, directly or indirectly, from combinations of thespecified ingredients in the specified amounts. In one example, thecomposition includes crenolanib or a pharmaceutically acceptable saltthereof in an amount sufficient for the treatment of a disease.

As used herein, the terms “FLT3 mutated proliferative disorder(s)”,“disorder related to FLT3,” or “disorders related to FLT3 receptor,” or“disorders related to FLT3 receptor tyrosine kinase,” “a deregulatedFLT3 receptor tyrosine kinase disease” or “FLT3 driven cellproliferative disorder” includes diseases associated with or implicatingFLT3 activity, for example, mutations leading to constitutive activationof FLT3. Examples of “FLT3 mutated proliferative disorder(s)” includedisorders resulting from over stimulation of FLT3 due to mutations inFLT3, or disorders resulting from abnormally high amount of FLT3activity due to abnormally high amount of mutations in FLT3. It is knownthat over-activity of FLT3 has been implicated in the pathogenesis ofmany diseases, including the following listed cell proliferativedisorders, neoplastic disorders and cancers. Non-limiting examples ofproliferative disorders for treatment with the present invention includeleukemia, myeloma, myeloproliferative disease, myelodysplastic syndrome,idiopathic hypereosinophilic syndrome (HES), bladder cancer, breastcancer, cervical cancer, CNS cancer, colon cancer, esophageal cancer,head and neck cancer, liver cancer, lung cancer, nasopharyngeal cancer,neuroendocrine cancer, ovarian cancer, pancreatic cancer, prostatecancer, renal cancer, salivary gland cancer, small cell lung cancer,skin cancer, stomach cancer, testicular cancer, thyroid cancer, uterinecancer, and hematologic malignancy.

As used herein, the terms “proliferative disorder(s)” and “cellproliferative disorder(s)” refer to excess cell proliferation of one ormore subset of cells in a multicellular organism resulting in harm (i.e.discomfort or decreased life expectancy) to the multicellular organism.Cell proliferative disorders can occur in different types of animals andhumans. As used herein, “cell proliferative disorders” includeneoplastic disorders.

As used herein, the term “neoplastic disorder” refers to a tumorresulting from abnormal or uncontrolled cellular growth. Examples ofneoplastic disorders include, but are not limited to the followingdisorders, for instance: the myeloproliferative disorders, such asthrombocytopenia, essential thrombocytosis (ET), agnogenic myeloidmetaplasia, myelofibrosis (MF), myelofibrosis with myeloid metaplasia(MMM), chronic idiopathic myelofibrosis (UIMF), and polycythemia vera(PV), the cytopenias, and pre-malignant myelodysplastic syndromes;cancers such as glioma cancers, lung cancers, breast cancers, colorectalcancers, prostate cancers, gastric cancers, esophageal cancers, coloncancers, pancreatic cancers, ovarian cancers, and hematologicalmalignancies, including myelodysplasia, multiple myeloma, leukemias, andlymphomas. Examples of hematological malignancies include, for instance,leukemias, lymphomas, Hodgkin's disease, and myeloma. Also, acutelymphocytic leukemia (ALL), acute myeloid leukemia (AML), acutepromyelocytic leukemia (APL), chronic lymphocytic leukemia (CLL),chronic myeloid leukemia (CML), chronic neutrophilic leukemia (CNL),acute undifferentiated leukemia (AUL), anaplastic large-cell lymphoma(ALCL), prolymphocytic leukemia (PML), juvenile myelomonocytic leukemia(JMML), adult T-cell ALL, AML, with trilineage myelodysplasia(AMLITMDS), mixed lineage leukemia (MLL), myelodysplastic syndromes(MDSs), myeloproliferative disorders (MPD), and multiple myeloma (MM).In certain embodiments, the present invention is directed at the use ofcrenolanib or a pharmaceutically acceptable salt thereof in an amountsufficient for the treatment of a neoplastic disorder.

In one embodiment of the present invention, the crenolanib or apharmaceutically acceptable salt thereof is provided at least one ofsequentially or concomitantly, with another chemotherapeutic agent in anewly diagnosed proliferative disease, to maintain remission, or arelapsed/refractory proliferative disease. The crenolanib or apharmaceutically acceptable salt thereof may be provided as a singleagent or in combination with another chemotherapeutic agent fortreatment of pediatric patient with the proliferative disease. Thecrenolanib or a pharmaceutically acceptable salt thereof may also beprovided as a single agent to at least one of post standard inductiontherapy, or high dose induction therapy, in newly diagnosedproliferative disease. The crenolanib or a pharmaceutically acceptablesalt thereof may also be provided as a single agent in treatment ofpatients with the proliferative disease that is either refractory to, orhas relapsed after prior treatment with a chemotherapeutic agent.Finally, the patient may be refractory to at least one other tyrosinekinase inhibitor prior to treatment.

In a further embodiment, the present invention can be combined withanother therapy as a combination therapy for treating or inhibiting theonset of a cell proliferative disorder related to FLT3 in a subject. Thecombination therapy comprises the administration of a therapeuticallyeffective amount of a compound of the present invention and one or moreother anti-cell proliferation therapies including, but not limited to,chemotherapy and radiation therapy.

In an embodiment of the present invention, a compound of the presentinvention may be administered in combination with chemotherapy. Usedherein, chemotherapy refers to a therapy involving a chemotherapeuticagent. A variety of chemotherapeutic agents may be used in combinationwith the present invention. By way of example only, taxane compounds,specifically docetaxel, is safely administered in combination with acompound of the present invention in a dosage of 75 mg per square meter(mg/m²) of body surface area.

Chemotherapy is known to those skilled in the art. The appropriatedosage and scheme for chemotherapy will be similar to those alreadyemployed in clinical therapies wherein the chemotherapy is delivered incombination with other therapies or used alone.

In another embodiment of the present invention, compounds of the presentinvention may be administered in combination with radiation therapy.Used herein, “radiation therapy” refers to a therapy that comprises theexposure of a subject in need to radiation. Radiation therapy is knownto those skilled in the art. The appropriate dosage and scheme forradiation therapy will be similar to those already employed in clinicaltherapies wherein the radiation therapy is delivered in combination withother therapies or used alone.

In another embodiment of the present invention, the compounds of thepresent invention may be administered in combination with a targetedtherapy. As used herein, “targeted therapy” refers to a therapytargeting a particular class of proteins involved in tumor developmentor oncogenic signaling. For example, tyrosine kinase inhibitors againstvascular endothelial growth factor have been used in treating cancers.

The present invention also includes methods that include the use of asecond pharmaceutical agent in addition to compounds of the presentinvention, the two may be administered simultaneously or sequentially(in either order).

In one embodiment, the present invention is of the compound havingformula I:

or a pharmaceutically acceptable salt or solvate thereof, in atherapeutically or prophylactically effective amount against aproliferative disease is selected from at least one of a leukemia,myeloma, myeloproliferative disease, myelodysplastic syndrome,idiopathic hypereosinophilic syndrome (HES), bladder cancer, breastcancer, cervical cancer, CNS cancer, colon cancer, esophageal cancer,head and neck cancer, liver cancer, lung cancer, nasopharyngeal cancer,neuroendocrine cancer, ovarian cancer, pancreatic cancer, prostatecancer, renal cancer, salivary gland cancer, small cell lung cancer,skin cancer, stomach cancer, testicular cancer, thyroid cancer, uterinecancer, and hematologic malignancy. Pharmaceutically acceptable saltsincluding hydrochloride, phosphate and lactate are prepared in a mannersimilar to the benzenesulfonate salt and are well known to those ofmoderate skill in the art.

Compounds of the present invention may be administered to a subjectsystemically, for example, orally, intravenously, subcutaneously,intramuscular, intradermal or parenterally. The compounds of the presentinvention can also be administered to a subject locally.

Compounds of the present invention may be formulated for slow-release orfast-release with the objective of maintaining contact of compounds ofthe present invention with targeted tissues for a desired range of time.

Compositions suitable for oral administration include solid forms, suchas pills, tablets, caplets, capsules, granules, and powders, liquidforms, such as solutions, emulsions, and suspensions. Forms useful forparenteral administration include sterile solutions, emulsions andsuspensions.

The daily dosage of the compounds of the present invention may be variedover a wide range from 50 to 500 mg per adult human per day. For oraladministration, the compositions are preferably provided in the form oftablets containing 20 and 100 milligrams. The compounds of the presentinvention may be administered on a regimen up to three times or more perday. Preferably three times per day. Optimal doses to be administeredmay be determined by those skilled in the art, and will vary with thecompound of the present invention used, the mode of administration, thetime of administration, the strength of the preparation, and the detailsof the disease condition. Factors associated with patientcharacteristics, such as age, weight, and diet will call for dosageadjustments.

Preparation of the compounds of the present invention. General syntheticmethods, which may be referred to for preparing the compounds of formulaI are provided in U.S. Pat. No. 5,990,146 (issued Nov. 23, 1999)(Warner-Lambert Co.) and PCT published application numbers WO 99/16755(published Apr. 8, 1999) (Merck & Co.) WO 01/40217 (published Jul. 7,2001) (Pfizer, Inc.), US Patent Application No. US 2005/0124599 (Pfizer,Inc.) and U.S. Pat. No. 7,183,414 (Pfizer, Inc.), relevant portionsincorporated herein by reference.

Pharmaceutically acceptable salts such as hydrochloride, phosphate andlactate are prepared in a manner similar to the benzenesulfonate saltand are well known to those of moderate skill in the art. The followingrepresentative compounds of the present invention are for exemplarypurposes only and are in no way meant to limit the invention, includingCrenolanib as Crenolanib Besylate, Crenolanib Phosphate, CrenolanibLactate, Crenolanib Hydrochloride, Crenolanib Citrate, CrenolanibAcetate, Crenolanib Toluenesulphonate and Crenolanib Succinate.

SUMMARY OF EXAMPLES Example 1

Patient harbored a de novo FLT3-ITD mutation and an acquired FLT3-D835TKD mutation. Following progression on another FLT3 inhibitor, thepatient achieved a hematologic benefit categorized as a CR on crenolanibbesylate therapy, and was bridged to a curative allogeneic stem celltransplant.

Example 2

Patient harbored a de novo FLT3-ITD mutation and an acquired FLT3-D835TKD mutation. Following progression on another FLT3 inhibitor, thepatient achieved hematologic benefit categorized as a CRi on crenolanibbesylate therapy, and was bridged to a curative allogeneic stem celltransplant.

Example 3

Patient harbored acquired FLT-ITD and FLT3-D835 TKD mutations. Followingprogression on cytotoxic chemotherapy and an autologous stem celltransplant, the patient achieved hematological benefit categorized asCRi on crenolanib besylate therapy, and was bridged to a curativeallogeneic stem cell transplant.

Example 4

Patient harbored an acquired FLT3-ITD mutation. Following progression oncytotoxic chemotherapy, the patient achieved hematological benefitcharacterized as CRi on crenolanib besylate therapy, and was bridged toa curative allogeneic stem cell transplant.

Example 1

Effect of Crenolanib Besylate Therapy in a Relapsed/Refractory AMLPatient with a de novo FLT3-ITD Mutation and Acquired FLT3-D835 TKDMutation: CR and Bridge to Transplant.

A 34 year old, 82.28 kg male diagnosed with AML in July 2012. At initialdiagnosis, laboratory testing revealed elevated peripheral blood andbone marrow blasts. The patient was positive for a de novo FLT3-ITDmutation, categorizing him as a high risk AML patient, which isassociated with poor prognosis, increased cumulative incidence ofrelapse and shortened overall survival.

The patient was initially treated with induction chemotherapy includinga standard dose of cytarabine given as a continuous infusion for 7 daysand 3 days of daunorubicin delivered intravenously. Following 1 cycle ofinduction therapy, the patient's bone marrow showed no evidence of AMLand remission was confirmed. To maintain the clinical remission, twocycles of consolidation therapy with high dose cytarabine werecompleted. Approximately 1 month later, a bone marrow biopsy showed thatthe patient had relapsed. With no other approved standard treatmentoptions available, the patient was enrolled on a phase I clinical trialfor relapsed and refractory AML patients, where he was treated twicedaily with an oral investigational FLT3 tyrosine kinase inhibitor, FLT3tyrosine kinase inhibitor Y. Following approximately 3 months of FLT3tyrosine kinase inhibitor Y treatment, the patient's disease progressedand he was withdrawn from the investigational study.

Further analysis showed that the patient had acquired a FLT3-TKDmutation in addition to the FLT3-ITD mutation that was present uponinitial treatment. Presence of both the FLT3-ITD and FLT3-TKD mutationsplaced the patient in an even higher risk group. Due to the increasedaggressive nature of the patient's disease, he was treated with salvagehigh dose cytarabine chemotherapy and hydroxyurea. Despiteadministration of the salvage cytotoxic regimens, there was nosignificant decrease in the patient's bone marrow blast counts. Thepatient discontinued both therapies.

To overcome resistance to prior therapy, the patient was provided singleagent oral crenolanib besylate on a clinical trial for relapsed orrefractory AML patients with a FLT3-D835 TKD mutation (NCT01522469). Atbaseline, the patient presented with 75% bone marrow blasts. The patientbegan treatment with 100 mg of oral crenolanib three times daily.Despite decreasing the crenolanib dose to 80 mg three times daily, after29 days of therapy a bone marrow biopsy revealed that crenolanibovercame prior FLT3 tyrosine kinase inhibitor resistance and the patientachieved complete remission (CR). The sustained clearance of bone marrowblasts made the patient eligible for stem cell transplant (see Table 1).The patient discontinued crenolanib therapy and underwent allogeneicstem cell transplant.

Table 1 illustrates the ability of crenolanib to clear malignantleukemia in the bone marrow of Example 1, a relapsed/refractory AMLpatient with a de novo FLT3-ITD mutation and acquired FLT3-D835 TKDmutation, after only 29 days of therapy

Days on Bone Marrow Study Drug Blast (%) 0 75 29 0 57 1

Example 2

Effect of Crenolanib Besylate Therapy in a Relapsed/Refractory AMLPatient with a de novo FLT3 ITD Mutation and Acquired FLT3-D835 TKDMutation: CRi and Bridge to Transplant.

A 45 year old, 49.7 kg female diagnosed with AML in February 2012. Atinitial diagnosis, laboratory testing revealed an elevated bone marrowblast percentage of 65%. The patient was positive for a de novo FLT3-ITDmutation, categorizing her as a high risk AML patient, which isassociated with poor prognosis, increased cumulative incidence ofrelapse and shortened overall survival.

The patient was initially treated with induction chemotherapy includinga standard dose of cytarabine given as a continuous infusion for 5 daysand 3 days of idaurubicin given intravenously. Following 1 cycle ofinduction therapy, the patient achieved a clinical complete remission.Laboratory tests showed a decrease in bone marrow blast percentage to 1%at week 5. To maintain the clinical remission, consolidation therapywith high dose cytarabine at 3 g/m² every 12 hours on days 1, 3, and 5was initiated for one cycle. In preparation for a stem cell transplant,the patient underwent an observational bone marrow biopsy. At week 12the bone marrow biopsy showed that the patient had relapsed, with a bonemarrow blast percentage increase to 57%. In an effort to achieve asecond remission, the patient was treated with salvage chemotherapyconsisting of a combination of mitoxantrone, etoposide and cytarabine.At week 16, a bone marrow biopsy revealed that the patient had achieveda second complete remission with 3% bone marrow blasts. In preparationfor a stem cell transplant, the patient underwent an observational bonemarrow biopsy at week 20. The biopsy results indicated that the patientexperienced a second relapse, with a bone marrow blast percentage of30%. With no other approved standard treatment options available, thepatient was enrolled on a clinical trial for relapsed and refractory AMLpatients, where she was treated daily with an oral investigational FLT3tyrosine kinase inhibitor, FLT3 tyrosine kinase inhibitor X, at doselevel 1. Following one treatment cycle of FLT3 tyrosine kinase inhibitorX, the patient presented with an elevated bone marrow blast percentageof 38%. Further analysis showed that the patient had acquired a FLT3-TKDmutation in addition to the FLT3-ITD mutation that was present uponinitial treatment. Presence of both the FLT3-ITD and FLT3-TKD mutationsplaced the patient in an even higher risk group. Due to the increasedaggressive nature of the patient's disease, the daily dose of FLT3tyrosine kinase inhibitor X was increased by 100% to dose level 2.Despite the increased dose of FLT3 tyrosine kinase inhibitor X, thepatient experienced an increase in bone marrow blasts to 60%. Thepatient discontinued the FLT3 tyrosine kinase inhibitor Xinvestigational study.

To overcome resistance to prior therapy with FLT3 tyrosine kinaseinhibitor X, the patient was provided single agent oral crenolanibbesylate on a clinical trial for relapsed or refractory AML patientswith a FLT3-D835 mutation (NCT01522469). At baseline, the patientpresented with 91% bone marrow blasts and 4800 units/uL of absolutecirculating peripheral blood blasts. The patient began treatment with 80mg of oral crenolanib three times daily. After only 14 days ofcrenolanib therapy, the patient achieved complete clearance of malignantleukemic blasts in her peripheral blood. Over the course of 65 days oftherapy, a bone marrow biopsy revealed that crenolanib overcame priorFLT3 tyrosine kinase inhibitor resistance and the patient achievedcomplete remission with incomplete blood count recovery (CRi). Adecrease in bone marrow blasts to 4-5% made the patient eligible forstem cell transplant (see Tables 1 and 2). The patient discontinuedcrenolanib therapy and underwent allogeneic stem cell transplant.

Table 1 illustrates the ability of crenolanib to clear malignantleukemia in the peripheral blood of Example 2, a relapsed/refractory AMLpatient with a de novo FLT3-ITD mutation and acquired FLT3-D835 TKDmutation, after only 14 days of therapy;

Days on Absolute Peripheral Study Drug Blast Count (units/uL) 1 4800 32747 4 250 7 49 9 35 14 0 21 0 28 0 37 0 38 0 39 0 40 0 41 0 42 0 43 045 0 46 0 47 0 48 0 49 0 50 0 51 0 52 0 69 0

Table 2 illustrates the ability of crenolanib to clear malignantleukemia in the bone marrow of Example 2, a relapsed/refractory AMLpatient with a de novo FLT3-ITD mutation and acquired FLT3-D835 TKDmutation, for a sustained period of 65 days following immediate relapseon another investigational FLT3 inhibitor;

Days on Bone Marrow FLT3 Inhibitor Study Drug Blast (%) FLT3 Inhibitor X0 30 28 38 42 60 Crenolanib 0 91 21 32 35 2 65 4-5

Example 3

Effect of Crenolanib Besylate Therapy in a Relapsed/Refractory AMLPatient with acquired FLT3-ITD and FLT3-D835 TKD Mutations: CRi andBridge to Transplant.

A 44 year old, 59.2 kg female diagnosed with AML December 2011.Following initial diagnosis the patient was treated with 7+3 inductionchemotherapy, followed by consolidation therapy with 1 cycle of highdose cytarabine. Five months later the patient underwent autologous stemcell transplantation with etoposide and busulfan conditioning. There wasno evidence of clinical response following transplant. Laboratorytesting revealed that the patient's circulating peripheral blood blastwere elevated two months later and her bone marrow blast percentage was42% three months later. Additionally, it was discovered that the patienthad acquired both a FLT3-ITD and FLT3-D835 TKD mutation. Given the invitro FLT3 target specificity of crenolanib for both of theconstitutively active mutations, the patient was initiated on the phaseII crenolanib monotherapy clinical trial (NCT01522469). At baseline (Day0), before administration of crenolanib besylate, the patient hadabsolute circulating peripheral blood blasts of 196 units/uL and 60-70%bone marrow blasts. The patient was treated with 100 mg of crenolanibbesylate three times daily. After only 15 days of crenolanib therapy,the patient achieved complete clearance of malignant leukemic blasts inher peripheral blood. After 33 days of therapy, a bone marrow biopsyrevealed that while on crenolanib therapy the patient achieved acomplete remission with incomplete blood count recovery (CRi). Adecrease in bone marrow blasts to 5% made the patient eligible for stemcell transplant. The patient discontinued crenolanib therapy to undergoallogeneic stem cell transplantation conditioning. The patientdiscontinued crenolanib therapy and underwent allogeneic stem celltransplant.

Table 3 illustrates the ability of crenolanib to clear malignantleukemia in the peripheral blood of Example 3, a heavily pretreatedrelapsed/refractory AML patient with acquired FLT3-ITD and FLT3-D835 TKDmutations, after only 15 days of therapy;

Days on Absolute Peripheral Study Drug Blast Count (units/uL) 0 196 1414 15 0 16 0 17 0 18 0 28 0 29 0 31 0 32 0 33 0 39 0 42 0 44 0 45 0 46 047 0 48 0 49 0 50 0 51 0 52 0

Table 4 illustrates the ability of crenolanib to clear malignantleukemia in the bone marrow of Example 3, a heavily pretreatedrelapsed/refractory AML patient with acquired FLT3-ITD and FLT3-D835 TKDmutations, for a sustained period of 33 days.

Days on Bone Marrow Study Drug Blast (%) 0 60-70 27 10 33 5

Example 4

Effect of Crenolanib Besylate Therapy in a Relapsed/Refractory AMLPatient with an acquired FLT3-ITD Mutation: CRi and Bridge toTransplant.

A 51 year old, 60.6 kg female diagnosed with FLT3-negative AML January2012. Following initial diagnosis the patient was treated with standard7+3 induction chemotherapy to which complete remission was achieved. Thepatient was then treated with 4 cycles of high dose cytarabineconsolidation therapy. Laboratory testing revealed that the patientprogressed on consolidation therapy. An acquired FLT3-ITD mutation wasnoted upon relapse and the patient was enrolled on the phase IIcrenolanib besylate monotherapy clinical trial (NCT01522469). Atbaseline (Day 0), before administration of crenolanib besylate, thepatient had absolute circulating peripheral blood blasts of 198 units/uLand 76% bone marrow blasts. The patient was treated with 100 mg ofcrenolanib besylate three times daily. After only 15 days of crenolanibtherapy, the patient achieved complete clearance of malignant leukemicblasts in her peripheral blood. After 29 days of therapy, a bone marrowbiopsy revealed that while on crenolanib therapy the patient achieved acomplete remission with incomplete blood count recovery (CRi). Asustained level of bone marrow leukemic blasts at 1% qualified thepatient for a stem cell transplant. The patient discontinued crenolanibtherapy and underwent allogeneic stem cell transplant.

Table 3 illustrates the ability of crenolanib to clear malignantleukemia in the peripheral blood of Example 4, a relapsed/refractory AMLpatient with an acquired FLT3-ITD mutation, after only 15 days oftherapy;

Days on Absolute Peripheral Study Drug Blast Count (cells/uL) 0 198 1130 8 19 15 0 22 0 29 0 58 0

Table 4 illustrates the ability of crenolanib to clear malignantleukemia in the bone marrow of Example 4, a relapsed/refractory AMLpatient with an acquired FLT3-ITD mutation, after only 29 days oftherapy.

Days on Bone Marrow Study Drug Blast (%) 0 76 29 1 58 1

It is contemplated that any embodiment discussed in this specificationcan be implemented with respect to any method, kit, reagent, orcomposition of the invention, and vice versa. Furthermore, compositionsof the invention can be used to achieve methods of the invention.

It will be understood that particular embodiments described herein areshown by way of illustration and not as limitations of the invention.The principal features of this invention can be employed in variousembodiments without departing from the scope of the invention. Thoseskilled in the art will recognize, or be able to ascertain using no morethan routine experimentation, numerous equivalents to the specificprocedures described herein. Such equivalents are considered to bewithin the scope of this invention and are covered by the claims.

All publications and patent applications mentioned in the specificationare indicative of the level of skill of those skilled in the art towhich this invention pertains. All publications and patent applicationsare herein incorporated by reference to the same extent as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference.

The use of the word “a” or “an” when used in conjunction with the term“comprising” in the claims and/or the specification may mean “one,” butit is also consistent with the meaning of “one or more,” “at least one,”and “one or more than one.” The use of the term “or” in the claims isused to mean “and/or” unless explicitly indicated to refer toalternatives only or the alternatives are mutually exclusive, althoughthe disclosure supports a definition that refers to only alternativesand “and/or.” Throughout this application, the term “about” is used toindicate that a value includes the inherent variation of error for thedevice, the method being employed to determine the value, or thevariation that exists among the study subjects.

As used in this specification and claim(s), the words “comprising” (andany form of comprising, such as “comprise” and “comprises”), “having”(and any form of having, such as “have” and “has”), “including” (and anyform of including, such as “includes” and “include”) or “containing”(and any form of containing, such as “contains” and “contain”) areinclusive or open-ended and do not exclude additional, unrecitedelements or method steps.

The term “or combinations thereof” as used herein refers to allpermutations and combinations of the listed items preceding the term.For example, “A, B, C, or combinations thereof” is intended to includeat least one of: A, B, C, AB, AC, BC, or ABC, and if order is importantin a particular context, also BA, CA, CB, CBA, BCA, ACB, BAC, or CAB.Continuing with this example, expressly included are combinations thatcontain repeats of one or more item or term, such as BB, AAA, AB, BBC,AAABCCCC, CBBAAA, CABABB, and so forth. The skilled artisan willunderstand that typically there is no limit on the number of items orterms in any combination, unless otherwise apparent from the context.

As used herein, words of approximation such as, without limitation,“about”, “substantial” or “substantially” refers to a condition thatwhen so modified is understood to not necessarily be absolute or perfectbut would be considered close enough to those of ordinary skill in theart to warrant designating the condition as being present. The extent towhich the description may vary will depend on how great a change can beinstituted and still have one of ordinary skilled in the art recognizethe modified feature as still having the required characteristics andcapabilities of the unmodified feature. In general, but subject to thepreceding discussion, a numerical value herein that is modified by aword of approximation such as “about” may vary from the stated value byat least ±1, 2, 3, 4, 5, 6, 7, 10, 12 or 15%.

All of the compositions and/or methods disclosed and claimed herein canbe made and executed without undue experimentation in light of thepresent disclosure. While the compositions and methods of this inventionhave been described in terms of preferred embodiments, it will beapparent to those of skill in the art that variations may be applied tothe compositions and/or methods and in the steps or in the sequence ofsteps of the method described herein without departing from the concept,spirit and scope of the invention. All such similar substitutes andmodifications apparent to those skilled in the art are deemed to bewithin the spirit, scope and concept of the invention as defined by theappended claims.

REFERENCES

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What is claimed is:
 1. A method for treating a hematologic malignancythat comprises a mutated FMS-like Tyrosine Kinase-3 (FLT3) in a patientcomprising administering to the patient a therapeutically effectiveamount of Crenolanib or a pharmaceutically acceptable salt thereof,thereby treating the hematologic malignancy.
 2. The method of claim 1,wherein the hematologic malignancy is selected from at least one ofleukemia, myeloma, myeloproliferative disease, or myelodysplasticsyndrome.
 3. The method of claim 1, wherein the therapeuticallyeffective amount of Crenolanib or pharmaceutically acceptable saltthereof are from about 50 to 500 mg per day, 100 to 450 mg per day, 200to 400 mg per day, 300 to 500 mg per day, 350 to 500 mg per day, or 400to 500 mg per 15 day.
 4. The method of claim 1, wherein thetherapeutically effective amount of Crenolanib or pharmaceuticallyacceptable salt thereof is administered at least one of continuously,intermittently, systemically, or locally.
 5. The method of claim 1,wherein the hematologic malignancy that is characterized by mutated FLT3and is selected from at least one of Hodgkin's disease, myeloma, acutelymphocytic leukemia (ALL), acute myeloid leukemia (AML), acutepromyelocytic leukemia (APL), chronic lymphocytic leukemia (CLL),chronic myeloid leukemia (CML), chronic neutrophilic leukemia (CNL),acute undifferentiated leukemia (AUL), anaplastic large-cell lymphoma(ALCL), prolymphocytic leukemia (PML), juvenile myelomonocytic leukemia(JMML), adult T-cell ALL, AML, with trilineage myelodysplasia(AMLITMDS), mixed lineage leukemia (MLL), myelodysplastic syndromes(MDSs), myeloproliferative disorders (MPD), or multiple myeloma (MM). 6.The method of claim 1, wherein the therapeutically effective amount ofCrenolanib or a pharmaceutically acceptable salt thereof is administeredorally, intravenously, or intraperitoneally.
 7. The method according toclaim 1, wherein the Crenolanib is Crenolanib besylate Crenolanibphosphate, Crenolanib lactate, Crenolanib hydrochloride, Crenolanibcitrate, Crenolanib acetate, Crenolanib toluenesulphonate and Crenolanibsuccinate.
 8. The method of claim 1, wherein the FLT3 is at least one ofFLT3-internal tandem duplication (FLT3-ITD) or FLT3-tyrosine kinasedomain (FLT3-TKD) mutant.
 9. The method of claim 1, wherein thetherapeutically effective amount of Crenolanib or a pharmaceuticallyacceptable salt thereof is administered up to three times or more a dayfor as long as the subject is in need of treatment for the proliferativedisorder.
 10. The method of claim 1, wherein the therapeuticallyeffective amount of Crenolanib or a pharmaceutically acceptable saltthereof is provided at least one of sequentially or concomitantly, withanother pharmaceutical agent in a newly diagnosed proliferative disorderpatient, to maintain remission of an existing patient, or arelapsed/refractory proliferative disease patient.
 11. The method ofclaim 1, wherein the therapeutically effective amount of Crenolanib or apharmaceutically acceptable salt thereof is provided as a single agentor in combination with another pharmaceutical agent in a patient with anewly diagnosed proliferative disorder, to maintain remission, or arelapsed/refractory proliferative disease patient.
 12. The method ofclaim 1, wherein the therapeutically effective amount of Crenolanib or apharmaceutically acceptable salt thereof is provided as a single agentor in combination with another pharmaceutical agent in a newly diagnosedproliferative disorder pediatric patient, to maintain remission, or arelapsed/refractory proliferative disorder pediatric patient.
 13. Themethod of claim 1, wherein the patient is relapsed/refractory to otherFLT3 tyrosine kinase inhibitors or another chemotherapy.
 14. A methodfor treating a patient suffering from a hematologic malignancycomprising: identifying the patient in need of therapy for themalignancy; and administering to the patient in need of such treatment atherapeutically effective amount of Crenolanib or a salt thereof,wherein the cellular disorder is characterized by deregulated FLT3receptor tyrosine kinase activity, wherein the malignancy is selectedfrom at least one of leukemia, myeloma, myeloproliferative disease,myelodysplastic syndrome, Hodgkin's disease, myeloma, acute lymphocyticleukemia (ALL), acute myeloid leukemia (AML), acute promyelocyticleukemia (APL), chronic lymphocytic leukemia (CLL), chronic myeloidleukemia (CML), chronic neutrophilic leukemia (CNL), acuteundifferentiated leukemia (AUL), anaplastic large-cell lymphoma (ALCL),prolymphocytic leukemia (PML), juvenile myelomonocytic leukemia (JMML),adult T-cell ALL, AML, with trilineage myelodysplasia (AMLITMDS), mixedlineage leukemia (MLL), myelodysplastic syndromes (MDSs),myeloproliferative disorders (MPD), or multiple myeloma (MM).
 15. Themethod of claim 14, wherein the Crenolanib or a salt thereof isadministered orally, intravenously, or intraperitoneally.
 16. The methodof claim 14, wherein the Crenolanib or a salt thereof is at least one ofCrenolanib besylate, Crenolanib phosphate, Crenolanib lactate,Crenolanib hydrochloride, Crenolanib citrate, Crenolanib acetate,Crenolanib touluenesulphonate and Crenolanib succinate.
 17. The methodof claim 14, wherein the FLT3 is at least one of FLT3-ITD or FLT3-TKD.18. The method of claim 14, wherein the Crenolanib or a salt thereof isprovided at least one of sequentially or concomitantly, with anotherchemotherapeutic agent in a newly diagnosed proliferative disease, tomaintain remission, or a relapsed/refractory proliferative disease. 19.The method of claim 14, wherein the Crenolanib or a salt thereof isprovided as a single agent or in combination with anotherchemotherapeutic agent for treatment of pediatric patient with theproliferative disease.
 20. The method of claim 14, wherein theCrenolanib or a salt thereof is provided as a single agent to at leastone of post standard induction therapy, or high dose induction therapy,in newly diagnosed proliferative disease.
 21. The method of claim 14,wherein the Crenolanib or a salt thereof is provided as a single agentin treatment of patients with the proliferative disease that is eitherrefractory to, or has relapsed after prior treatment with achemotherapeutic agent.
 22. The method of claim 14, wherein the patientis refractory to at least one other tyrosine kinase inhibitor or anotherchemotherapy.
 23. A method for treating a patient suffering fromleukemia comprising: obtaining a sample from the patient suspected ofhaving leukemia; determining from the patient sample that the patienthas a deregulated FLT3 receptor tyrosine kinase; and administering tothe patient in need of such treatment a therapeutically effective amountof Crenolanib or a salt thereof, wherein the leukemia is characterizedby deregulated FLT3 receptor tyrosine kinase activity.
 24. The method ofclaim 23, wherein the hematologic malignancy or leukemia is selectedfrom at least one of Hodgkin's disease, myeloma, acute lymphocyticleukemia (ALL), acute myeloid leukemia (AML), acute promyelocyticleukemia (APL), chronic lymphocytic leukemia (CLL), chronic myeloidleukemia (CML), chronic neutrophilic leukemia (CNL), acuteundifferentiated leukemia (AUL), anaplastic large-cell lymphoma (ALCL),prolymphocytic leukemia (PML), juvenile myelomonocytic leukemia (JMML),adult T-cell ALL, AML, with trilineage myelodysplasia (AMLITMDS), mixedlineage leukemia (MLL), myelodysplastic syndromes (MDSs),myeloproliferative disorders (MPD), or multiple myeloma (MM).
 25. Amethod for specifically inhibiting a deregulated FLT3 receptor tyrosinekinase comprising: obtaining a sample from a patient with a hematologicmalignancy; determining which receptor tyrosine kinases are deregulated;and administering to a mammal in need of such treatment atherapeutically effective amount of Crenolanib or a salt thereof,wherein the deregulated receptor tyrosine kinase is a FLT3 receptortyrosine kinase.
 26. The method of claim 25, wherein the therapeuticallyeffective amount of Crenolanib or a salt thereof is provided in anamount that decreases patient circulating peripheral blood blast count.27. The method of claim 25, wherein the therapeutically effective amountof Crenolanib or a salt thereof is provided in an amount that decreasesa patient bone marrow blast count.
 28. The method of claim 25, whereinthe hematologic malignancy is selected from at least one of leukemia,myeloma, myeloproliferative disease, or myelodysplastic syndrome. 29.The method of claim 25, wherein the therapeutically effective amount ofCrenolanib or a salt thereof is also provided prophylactically ateffective amounts are from about 50 to 500 mg 20 per day, 100 to 450 mgper day, 200 to 400 mg per day, 300 to 500 mg per day, 350 to 500 mg perday, or 400 to 500 mg per day.
 30. The method of claim 25, whereintherapeutically effective amount of Crenolanib or a salt thereof isadministered at least one of continuously, intermittently, systemically,or locally.
 31. The method of claim 25, wherein the deregulated FLT3 isdefined further as a mutated FLT3 is constitutively active.
 32. Themethod of claim 25, wherein therapeutically effective amount ofCrenolanib or a salt thereof is administered orally, intravenously, orintraperitoneally.
 33. The method of claim 25, wherein the Crenolanib isat least one of Crenolanib Besylate, Crenolanib Phosphate, CrenolanibLactate, Crenolanib Hydrochloride, Crenolanib Citrate, CrenolanibAcetate, Crenolanib Touluenesulphonate and Crenolanib SuccinateCrenolanib Besylate.
 34. The method of claim 25, wherein the FLT3 is atleast one of FLT3-ITD or FLT3-TKD.
 35. The method of claim 25, whereintherapeutically effective amount of Crenolanib or a salt thereof isadministered up to three times or more a day for as long as the subjectis in need of treatment for the proliferative disease.
 36. The method ofclaim 25, wherein the patient is provided treatment, and the methodfurther comprises the steps of obtaining one or more patient samples todetermine the effect of the treatment, and continuing treatment untilthe proliferative disease is reduced or eliminated.
 37. The method ofclaim 25, wherein therapeutically effective amount of Crenolanib or asalt thereof is provided at least one of sequentially or concomitantly,with another pharmaceutical agent in a newly diagnosed proliferativedisease patient, to maintain remission, or a relapsed/refractoryproliferative disease patient.
 38. The method of claim 25, whereintherapeutically effective amount of Crenolanib or a salt thereof isprovided as a single agent or in combination with another pharmaceuticalagent in a newly diagnosed proliferative disease patient, to maintainremission, or a relapsed/refractory proliferative disease patient. 39.The method of claim 25, wherein therapeutically effective amount ofCrenolanib or a salt thereof is provided as a single agent or incombination with another pharmaceutical agent in a newly diagnosedproliferative disease pediatric patient, to maintain remission, or arelapsed/refractory proliferative disease pediatric patient.
 40. Themethod of claim 25, wherein the patient is relapsed/refractory to aprior tyrosine kinase inhibitor or another chemotherapy.
 41. A methodfor treating a patient with a hematologic malignancy that comprises amutated FLT-3 comprising: obtaining a sample from the patient;determining if the patient that has become resistant to prior tyrosinekinase inhibitors or chemotherapy; and administering a therapeuticallyeffective amount of Crenolanib or a salt thereof to overcome theresistance to the prior protein tyrosine kinase inhibitors.
 42. Themethod of claim 41, wherein the disease is leukemia.
 43. The method ofclaim 42, wherein the disease is AML.